In the past modular floating docks have been created by the assembly of a number of floating subunits. These subunits include various geometric shapes with planar upper and lower surfaces. The subunits connect together to create docks and walkways having various shapes and sizes based on the consumers needs.
For example, U.S. Pat. Nos. 6,138,599 and 5,947,049 teach a buoyant walkway module for a boatlift. The device includes a plurality of elongated compartments having planar top and bottom surfaces. The device also includes planar ends for connecting the walkways together in an end to end relationship.
U.S. Pat. No. 5,251,560 teaches a water-float coupling device for coupling together hexagonally shaped floats having planar upper and lower surfaces.
U.S. Pat. No. 6,033,151 teaches a float unit having planar upper and lower surfaces and corrugated side surfaces. The corrugated side surfaces engage with adjacent floats to provide friction between the units.
U.S. Pat. Nos. 3,824,644 and 4,604,962 teach a substantially prismatic, floating element having rounded corner edges. The elements are provided with outwardly projecting eye lugs for attachment to adjacent elements. These elements are typically provided with bungholes to allow partial flooding of some or all of the units to lower their water line.
It is also known in the prior art to construct floating drive-on type docks. The docks are assembled from floating elements having various geometric shapes to create a dock which allows a boat operator to drive his/her boat directly onto the upper surface of the dock using the boats power.
For example, U.S. Pat. No. 5,941,660 teaches a watercraft support structure formed from a plurality of large rigid platforms that are coupled together by linking pins or insertion plugs. The structure includes multiple ramp, cradle, and flat platforms.
These devices work relatively well for docking large watercraft however, the upwardly extending hull guides and cylindrically shaped upper surface make these devices generally unsuitable for dual use as decks or walkways.
Other floating drive-on docks of the prior art are constructed of cubical subunits with tabs projecting from the vertical edges at or near the horizontal midline for attachment to adjacent units. The units have planar upper surface and lower surfaces. The floating units are provided with a gripping texture on one side and thus, are generally designed to be oriented only with the gripping surface upward.
For example, U.S. Pat. Nos. 5,529,013, 5,682,833, 5,947,050, 6,431,106 and 5,931,113 teach a floating drive-on dock assembled using the parallelepiped shaped units. The docks generally consist of two arms (single rows) of hollow and airtight floatation units. The arms each consist of three large cubes at the inward portion and three small cubes mounted at the distal end. Between the arms is an area open to the water surface. At the distal end of the two arms a floatation unit is utilized to connect the arms together to prevent the arms from spreading apart as a craft is driven onto the arms.
While these designs are functional, they have numerous shortcomings that have not been addressed in the art. For example, in order to provide guidance for the boat hull when used for drive-on docking, the planer surfaced cubes must be spaced apart leaving an open center between the two arms. The open center does not provide sufficient guiding for several types of boat hulls.
In addition, the narrow width of the arms, the lack of connection to floatation units on four sides, the open center, and the low buoyancy of the small cubes make these structures extremely unstable for pedestrian traffic and unsuitable for decks or walkways. This safety hazard is magnified when the docks are used at night.
Still further, the open nature of these docks combined with the wave action associated with large bodies of water often results in repeated splashing of water into the drive units of the docked watercraft and thus causes premature failure of important components of the watercraft drive system. Keeping a watercraft high and dry when not in use is important to protecting the machinery of the craft. This is particularly true of jet type propulsion systems and is critical when the craft is docked in salt water.
Thus, what is needed in the art is a modular docking element that is adapted for assembly into walkways, decks and drive-on docks to provide increased versatility and safety. The element should be multidirectional, having a surface specific to drive-on docking on one face and a surface specific to decks and walkways on a second face. Each of these faces should provide a surface which allows a watercraft to slide easily for drive-on docking without hull damage, while providing superior grip for pedestrian traffic. The floating element should also accommodate utilities, e.g. water and electricity throughout the dock and/or walkway when assembled. The assembled floating elements should also accommodate rigid members wherever they are needed throughout the dock to change the flex and buoyancy characteristics of the dock. Each individual floating element should optionally allow ballast to be added to alter the height, buoyancy and stability of an assembled dock or walkway.